Firearm accessories, such as scopes, lights, grips, night vision devices, and bipods, are typically attached to a firearm using a standardized mounting feature. One type of standardized mounting feature is commonly referred to as a “rail.” FIG. 1 illustrates a rail in a context of a sidearm. As shown, a sidearm 100 includes a rail 104 attached to an underside of a barrel assembly of the sidearm 100. The rail 104 enables an accessory having a clamp that is compatible with the rail 104 to be attached to the sidearm 100.
FIG. 2A illustrates one common configuration of a rail. The rail 204 shown in FIG. 2A is specified by U.S. Department of Defense standard number MIL-STD-1913 (also identified by North Atlantic Treaty Organization (“NATO”) specification number STANAG 2324). This rail is more commonly known as a “1913 rail,” or a “Picatinny rail.” Another common configuration of a rail is a NATO accessory rail, identified by NATO specification number STANAG 4694. Similar in configuration to the “1913 rail,” the NATO accessory rail is also colloquially identified by its acronym: “NAR.” Regardless of the precise designation, the 1913 rail, NAR, and similarly configured rails, are collectively referred to herein as “Picatinny-type” rails.
A number of mounting clamps have been developed for mounting accessories to rails. Typically the mounting clamps are configured to mount to a single type of rail. These mounting clamps have an attachment mechanism for clamping the accessory securely to the mounting rail. An example of a mounting clamp attached to the 1913 rail is illustrated in FIG. 2B. As shown, the Picatinny rail 204 of FIG. 2A is placed within a clamp 206. The clamp 206 includes a base 208 and a sidewall 212. The base includes mounting faces 218a, 218b, 218c, and 218d (collectively 218), each of which is configured to mount to a confronting mounting face 216a, 216b, 216c, and 216d (collectively 216) of the Picatinny-type rail 204. A flat face 220 of the Picatinny rail 204 is disposed so as to have a gap separating the flat face 220 and the face 222 of the base 208. This is because the Picatinny rail 204 is configured to be secured into position within the clamp 206 by contact between angled faces 218 and 216.
While not shown, the NAR rail, similar in configuration to the 1913 rail, is configured to mount within a NAR-compatible clamp through contact with: (1) two angled mounting faces analogous to one each of mounting faces 216a and 216b, and mounting faces 216c and 216d of the rail 204 shown in FIG. 2A; and (2) a flat face analogous to the flat face 220 of the rail 204. In other words, the NAR rail is configured to mount within a corresponding clamp by contact at three faces (two angled mounting faces and a flat face) whereas the 1913 rail is configured to mount within a corresponding clamp by contact with four angled mounting faces.